1. Field of the Invention
This invention relates to a diagnostic reagents, capture membranes, which are useful in removing specifically binding complexes from solutions and assay methods using such reagents. The specifically binding complexes include antigen/antibody complexes, DNA, anti-DNA (antibody to DNA) or Single Strand DNA Binding Protein (such as SSB from E. coli), DNA, DNA hybrids, RNA, RNA hybrids, and similar specifically binding complexes.
2. The Related Art
There are extensive teachings in the art of diagnostic assays and reagents involving specifically binding complexes. Antigen/antibody reactions are widely used to determine antigen and antibodies. The labeling of members of these complexes with detectable markers such as enzymes or florescent dyes is well known. The binding of antigen or antibodies and solid supports as a means of removing complexes from solutions is also known. The use of haptens such as biotin and anti-haptens such as streptavidin in diagnostic assay is extensively discussed in a review article that appears in Analytical Biochemistry 171, 1-32 (1988).
Biotin attached to a solid-support is described in U.S. Pat. Nos. 4,282,287, 4,478,914, and 4,656,202. These patents describe precise layering technique wherein biotin is first attached to a solid-surface and the subsequent application of successive layers of avidin and extender results in a controlled modification of surface characteristics.
European Patent No. 87,307,850.5 is directed toward a method for routine plant-virus diagnosis which includes biotin attached to a macro-molecule that is conjugated to a sample of probe DNA. The probe containing compound is applied to a solid-matrix which has a test sample of DNA derived from plant tissue immobilized thereon. The presence of the target sequence is determined by washing the matrix with enzyme linked avidin followed by assaying for enzyme activity associated with the matrix.
U.S. Pat. No. 4,467,031 describes an enzyme-immunoassay which utilizes the biotin-avidin system as a convenient and stable linking group for connecting a reporter enzyme to an antibody.
U.S. Pat. No. 4,228,237 describes the use of the biotin-avidin system in a method for detection and determination of ligands. A surface having an antibody for the ligand of interest attached thereto is reacted with a sample of the ligand followed by a second ligand specific antibody that is conjugated with biotin. This complex is then reacted with an avidin conjugated enzyme and the results are determined by measurement of enzyme activity.
U.S. Pat. No. 4,656,025 describes a screening assay for tumor globulin. A tumor globulin-biotin conjugate on ELISA plates is reacted with avidin conjugated enzyme and quantification of the tumor globulin bound to the plate is determined by the application of the appropriate chromogenic substrate thereto.
U.S. Pat. No. 4,535,057 describes an immunoassay having biotin conjugated to a solid support through an antibody-virus complex. This biotin-antibody virus complex is then reacted with avidin conjugated to a reporter group or a label and the presence of the label associated with the surface is indicative of the presence of virus in the sample.
U.S. Pat. Nos. 4,727,019, and 4,632,901 describe an immunoassay wherein avidin is attached to a solid support and binds a ligand present in the sample to the support. U.S. Pat. No. 4,298,685 describes a diagnostic reagent that also involves avidin immobilized on a solid support. U.S. Pat. No. 4,582,810 describes a detection system wherein a suspension of particles having avidin covalently bound thereto reacts with a biotin-antibody complex to form a complex which results in a flocculent appearing solution.
U.S. Pat. No. 4,550,075 describes a method for ligand determination based on the biotin-avidin system without any solid support.
U.S. Pat. No. 4,486,530 describes an immunometric assay process that comprises a ternary complex of an antigenic substance, and a first and second antibody bound to the antigen in which the complex is removed from solution by filtering through a membrane.
Clinical Chemistry, 34, No. 8, p. 1585 (1988) describes a monoclonal antibody based noncompetitive avidin-biotin assay for luteinizing hormone (LH) in urine.
U.S. Pat. No. 4,778,751, describes a method for measuring antigens which comprises: forming in a liquid phase reaction a soluble complex wherein an antigen (Ag.sub.1), antibody (Ag.sub.1) or hapten (H) is linked through, respectively, a specific antibody (Ab), antigen (Ag) or anti-hapten (Anti-H), to a matrix which is soluble in the liquid phase and carries a ligand (X), the matrix capable of being chemically attached to more than one specific antibody (Ab), antigen (Ag) or anti-hapten (Anti-H); forming an insolubilized complex comprising a solid support linked to the ligand (X) of the soluble complex through an anti-ligand (Y), the insolubilized complex carrying a label (Z) linked to the antigen (Ag.sub.1) through an anti-antigen (Anti-Ag.sub.1), to the antibody (Ab.sub.1) through an anti-antibody (Anti-Ab.sub.1) or to the hapten (H); washing the insolubilized complex; and observing the washed insolubilized complex for the presence of the label (Z) wherein the presence of the label (Z) is an indication of the level of the antigen (Ag.sub.1), antibody (Ab.sub.1) or hapten (H) in the sample.
European Patent Application No. 86111379.3 describes multilayer immunoassay test devices involving the use of labeled reagents comprising a chemical group having a detectable physical property such as fluorescence or color.
European Patent Application No. 88.308164.8 describes a method for determination of single-stranded DNA based on the binding of a single-stranded DNA to a single-stranded DNA-binding protein to which is bound a solid support.
Molecular Immunology, 34: 221-230 (1989) describes an ELISA system involving immobilization of biotinylated CAbs through linkage by streptavidin to biotinylated carrier proteins absorbed on polystyrene. The present invention provides technology for removal of specifically binding complexes from a solution and differs from the prior art in that the reagent of this invention is a porous membrane with a hapten preferably biotin bound directly or indirectly to the membrane.